Manual removal of a bobbin from a spindle, which always takes place when the yarn supply on the spindle is used up or a yarn winding being formed on the bobbin is completed, is often made difficult by binding of the bobbin on the spindle or by a housing which hinders access to the bobbin.
In order to be able to remove cops or bobbins jammed on spindle shafts without use of great force, it was previously proposed to arrange displaceable washers beneath the cop sleeve or bobbin, able to be coupled to a press-off mechanism which can be raised or lowered (DE-OS No. 2,334,012, equivalent to U.S. Pat. No. 3,962,856). It is further known to effect the release and doffing of the cop on ring spinning or ring twisting machines by means of a liftable fork bench or fork rail with forks or round pins which act on the yarn body (DE-Gm No. 1,980,127, equivalent to French Pat. No. 1,583,009; DE-OS No. 2,150,212).
These known apparatuses are costly on a plant scale and can lead, when put in operation, to damage to the yarn body or the sleeves. Apart from this, the possibility of their use is restricted. They can only be used for doffing or raising bobbins which present a free working surface, but not with bobbins which are surrounded by a housing, as is the case, for example, with wrap spinning apparatuses (DE-OS No. 2,753,349, equivalent to U.S. Pat. No. 4,170,101).